Pneumatic jack.



PATENTED APR. 4, 1905.

' G. N. COON.

. PNEUMATIC JACK.

APPLIUATIOR FILED run. w, 1903.

Patented April 4, 1906.

PATENT OFFICE.

CHARLES N. COON, MATTOON. ILLINOIS.

PNEUMATIC JACK.

SPECIFICATION forming part of Letters Patent No. 786,409, dated April 4,1905.

' Application and March 19,1903. SerialNo.148=616.

To all whom. it ntay concern:

Be it known that I, CHARLES N. Coon, a citizen of the United States, residing at Mattoon,

in the county of Coles and State of Illinois, have invented certain new and useful Improvements in Pneumatic Jacks; and 1 do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

- This invention relates to pneumatic liftingjacrks of a compound type.

The object of the invention is to produce a jack of this kind the construction of which permits the use of a maximum amount of lift- .in g power by increasing the area against which the air or other fluid pressure is brought to bear.

A further object is to produce such a jack which will be simple in construction, strong and durable in use, and which may be conveniently moved from place to place,

With these and other objects in view the invention consists of certain novel features of construction, combination, and arrangement of parts, as will be hereinafter more fully described, and particularly pointed out in the appended claim.

In the accompanying drawings, Figurel is a side elevation of the jack. Fig. 2 is a'central vertical section of the same. Fig. 3 is a horizontal sectional view on the line 3 3 of Fig. 1. Fig. 4 is a longitudinal sectional view through the air-inlet valve. Fig. 5 is a crosssectional view thereof on line'5 5 of Fig. 4.

In the drawings, 1 denotes the outer shell or cylinder of the jack, suitably mounted upon a base 2 and provided upon its upper end with a flanged guide band or cap 3.

4 denotes a hollow cylindrical piston which is adapted to slide within the shell or cylinder 1 and is closed at its upper end by a head 5, the upper part of which is suitably formed and serrated for engagement with the article to be lifted.

The lower inner end of the piston 4 is flanged, as shown at 4, and is also closed by a head or plate 6, which is bolted or screwed thereto, and between said head and the lower 'fianged end of the piston is clamped one web or portion of an annular angular packingring 7, of leather or other flexible material, the other web or portion of said packing-ring engaging the inner surface of the cylinder 1 and held in air-tight engagement with the same 7 by means of an expansive ring or band 8.

The piston 4 is guided in its outward and inward movements by the annular flanged guide band or cap 3, and it is further guided in these movements by a fixed upwardly-projecting hollow piston-rod or gu'idestandard 9, mounted in the base 2. The piston-rod 9 passes upwardly into the hollow piston 4 through a centrally-disp0sed stuffing-box 10, formed on the inner head or bottom plate of the piston, and has formed on its upper end a circular head or plate 12, which its within the piston 4. I

13 denotes a plate of somewhat less diameter than the head 12, to which the same is adapted to be secured or bolted. The plate 13 is provided with a centrally-disposed hole or opening 14, which when the plate 13 is in place is coincident with the passage through the piston-rod or standard 9. Between the plate 13 and the head 12 is clamped one web or portion of an annular angular packing-ring 14', of leather or other flexible material. the other web or portion of which engages the inner surface of the piston 4 and is held in air-tight engagement with the same by means of an expansive ring 15. The packing-ring 14 is similar in term and construction to the packing-ring 7, except that the engaging portion of the ring 7 projects downwardly, while that of the ring 14 projects upwardly, as shown. The expansive rings or bands 8 and 15 are adapted to lie in annular grooves formed in the edges of inner piston-head 6 and the plate 13, respectively, whereby they are held in place.

Air or other fluid is admitted to the pistonheads 5 and 6 through ports or passages 16 and 17, formed in the base 2. The air from the port or passage 16 enters the outer cylinder or shell 1 and bears directly upon the I outer face of the lower head or plate 6, while the air from port 17 enters an opening in the lower end of the hollow piston rod or standard 9 and passes upwardly through said hollow piston-rod and enters the interior of the hollow piston 4 above the plates 12 and 13 and bears against the inner surface of the head 5.

The ports 16 and 17 in the base '2 form a continuation of ports or passages 18 and 19, formed in the lower end of the side walls of the cylinder or shell 1, the said passages 18 and 19 being in connection at their upper ends with a three-way rotary valve 20, mounted in a casing 21, formed in one side of the cylinder 1, the said casing 21 being provided with inlet-ports 22 and 23 and a discharge-port 2%. The port 22 is provided with ascrew-tln'cadcd nipple25, to which is adapted to be connected the end of a hose or pipe leading to a suitable reservoir or other source of air-supply.

The port '23 of the valve-casing is in communication with a passage 25, formed in the side wall of the cylinder 1, which passage conimunicates with a hand air pump or compressor 26, fixed to the side of the cylinder 1. The pump or compressor '26 may be of any suitable construction, that shown in the drawings being of a compound type comprising two cylinders 27 and 28, arranged in vertical alinement upon the side of the jack-cylinder 1 and having an operating-handle 29 and suitable inlet and discharge valves.

The valve 20 is a three-way plug-valve and consists of a casing 21. in which is arranged a plug 21*, to one end of which is fixed an operating-handle 21". In the opposite end of the plug 21 is formed a valve-seat, in which is arranged a check-valve 30. The valve 30 is adapted to slide upon a guide rod or stem 31, fixed to the inner end of a threaded screw plug or head 32, which is adapted to be screwed into the end of the valve-plug 21. A spring 33 is coiled around the stem 31 between the head or plug 32 and the end of the valve, said spring tending to normally hold the valve closed upon its seat, the tension of the spring being regulated by screwing the head 32 in or out.

34 denotes a port formed in the plug 21 in communication with the outer end of the bore in which the check-valve 30 works, the port 34 being adapted upon rotation of the plug 21" to be brought into alinement with the discharge-port 24 of the valve-casing to admit air to the jack-cylinders. A central port or passage 35 in the plug 21" communicates with the check-valve cavity at the opposite end of the valve from the port 34, said passage 35 being provided with lateral branch passages 36, which are adapted to be brought into communication with the air-supply ports 22 and 23 in the valve-casing, which in turn communicate with the sources of air-supply. The valve-plug 21 is also adapted to be turned to with an air deliveryor exhaust port 37, formed 1 in the valve-casing 21.

355 denotes relief or discharge ports formed in the lower end of the piston 4, through which any air that may have accumulated in the piston below the'plate 12 may be permitted to escape, such escaping air passing upwardly between the piston-cylinder and the outer shell or cylinder 1 and escaping out between the flange 3 and the pump-cylinder.

39 denotes handles arranged upon the sides of the cylinder, by which the jack may be carried about. In practice air is admitted to the interior of the shell or cylinder and the piston from the sourceof supply through the valve 20 and controlled by said valve. The air thus admitted acts upon both the upper and lower heads of the piston, thereby doubling the amount of pressure upon the same, thus producing a jack of greatly-increased lifting power. \Vhile I have described air as the motive power, it is obvious that steam or other fluid may be substituted in place oi air to produce the same results.

From the foregoing description, taken in connection with the accompanying drawings, the construction and operation of the invention will be readily understood without requiring a more extended explanation.

Various changes in the form, proportion, and the minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of this invention.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

A lifting-jack of the class described,' comprising an outer cylinder having an opening in its upper head, a base closing its lower end, a hollow standard rising from the base and having a head at its upper end, the said cylinder being further provided with fluid-inlet passages, respectively communicating at. its base with the bore of the said hollow standard and directly with the interior of the cylinder, said cylinder being further provided with a valve-casing having a tapered bore, a port 24: with which said fluid-passages communicate, and inlet and exhaust ports, a valveplug in said'bore, said plug having a longitudinal bore in one end, a channel leading thereto and adapted to communicate with the inletport of the casing. and ports to communicate with the port 24 and the exhaust-ports respectively, a check-valve in said bore of the valve-plug, between the inlet-channel thereof and the before-mentioned ports with which said valve-plug is provided. said valved plug controlling the fluid-passages of the cylinder, and a hollow piston in the cylinder projecting through the opening in the cylinder-head, spaced from the cylinder, iavinga base-flange 7se,409 v I 8 engaging the cylinder and relief-openings in In testimony whereof I have hereunto set its sides, near its lower end, said hollow pismy hand in presence of two subscribing witton being internally engaged by the head of nesses.

the hollow standard and being closed at its CHARLES N. (JOON.

upper and lower ends, its closed lower end aving an opening through which the hollow standard extends, substantially as described.

\Vitnesses:

RAYMOND Coos, D. I. EWING. 

